title: N-formyl-methionyl-leucyl-phenylalanine (fMLP) promotes osteoblast differentiation via the N-formyl peptide receptor 1-mediated signaling pathway in human mesenchymal stem cells from bone marrow.
abstract: Binding of N-formyl-methionyl-leucyl-phenylalanine (fMLP) to its specific cell surface receptor, N-formyl peptide receptor (FPR), triggers different cascades of biochemical events, eventually leading to cellular activation. However, the physiological role of fMLP and FPR during differentiation of mesenchymal stem cells is unknown. In this study, we attempted to determine whether fMLP regulates differentiation of mesenchymal stem cells derived from bone marrow. Analysis by quantitative-PCR and flow cytometry showed significantly increased expression of FPR1, but not FPR2 and FPR3, during osteoblastic differentiation. fMLP, a specific ligand of FPR1, promotes osteoblastic commitment and suppresses adipogenic commitment under differentiation conditions. Remarkably, fMLP-stimulated osteogenesis is associated with increased expression of osteogenic markers and mineralization, which were blocked by cyclosporine H, a selective FPR1 antagonist. In addition, fMLP inhibited expression of peroxisome proliferator-activated receptor-γ1, a major regulator of adipocytic differentiation. fMLP-stimulated osteogenic differentiation was mediated via FPR1-phospholipase C/phospholipase D-Ca(2+)-calmodulin-dependent kinase II-ERK-CREB signaling pathways. Finally, fMLP promoted bone formation in zebrafish and rabbits, suggesting its physiological relevance in vivo. Collectively, our findings provide novel insight into the functional role of fMLP in bone biology, with important implications for its potential use as a therapeutic agent for treatment of bone-related disorders.
authors.affiliation: Department of Molecular Biology, College of Natural Science, Pusan National University, 30 Jangjeon Dong, Geumjeong gu, Busan 609-735, Korea.
authors.forename: Min Kyoung
authors.initials: MK
authors.lastname: Shin
authors.forename: Young Hoon
authors.initials: YH
authors.lastname: Jang
authors.forename: Hyun Jung
authors.initials: HJ
authors.lastname: Yoo
authors.forename: Dong Woo
authors.initials: DW
authors.lastname: Kang
authors.forename: Mi Hee
authors.initials: MH
authors.lastname: Park
authors.forename: Mi Kyoung
authors.initials: MK
authors.lastname: Kim
authors.forename: Ju Hyun
authors.initials: JH
authors.lastname: Song
authors.forename: Sang Doo
authors.initials: SD
authors.lastname: Kim
authors.forename: Gyesik
authors.initials: G
authors.lastname: Min
authors.forename: Hyung Keun
authors.initials: HK
authors.lastname: You
authors.forename: Kang-Yell
authors.initials: KY
authors.lastname: Choi
authors.forename: Yoe-Sik
authors.initials: YS
authors.lastname: Bae
authors.forename: Do Sik
authors.initials: do S
authors.lastname: Min
mesh_terms: D017667:Adipocytes / Q000166:cytology; D000818:Animals; D001854:Bone Marrow Cells / Q000166:cytology*; D054732:Calcium-Calmodulin-Dependent Protein Kinase Type 2 / Q000378:metabolism; D002454:Cell Differentiation; D016572:Cyclosporine / Q000494:pharmacology; D006801:Humans; D059630:Mesenchymal Stem Cells / Q000166:cytology*; D009240:N-Formylmethionine Leucyl-Phenylalanine / Q000494:pharmacology*; D010006:Osteoblasts / Q000166:cytology*; D047495:PPAR gamma / Q000378:metabolism; D010739:Phospholipase D / Q000378:metabolism; D011817:Rabbits; D044042:Receptors, Formyl Peptide / Q000737:chemistry / Q000502:physiology*; D015398:Signal Transduction; D010738:Type C Phospholipases / Q000378:metabolism
chemical_list: D047495:PPAR gamma; D044042:Receptors, Formyl Peptide; D009240:N-Formylmethionine Leucyl-Phenylalanine; D016572:Cyclosporine; D054732:Calcium-Calmodulin-Dependent Protein Kinase Type 2; D010738:Type C Phospholipases; D010739:Phospholipase D; C050025:cyclosporin H